>Our tests last year showed that *cool white* fluorescent bulbs didn't
>print cyanotype at all,
>may have printed pl/carbon, but as I recall not well (I only tested them
>with cyanotype).
The *cool white* florescent bulbs did print carbon, but they were must less
effective than *Daylight* bulbs.
>
>It apparently printed carbon and pl/pd as tested by Sandy King (I believe it
>was) but was slower and too contrasty in gum.
I did not personaly test the Daylight bulbs with pl/pd , but in my working
conditions with carbon these bulbs perform better than BL bulbs. My
problem with the BL bulbs is that with normal strength dichromate
sensitizers (2-3%) they give images very low in contrast.This seems to be
because light at about 350nm does not penetrate very far into the gelatin.
In order to get decent contrast with BL bulbs I had to use very weak
sensitizers, in the 1/8 -1/4 % range. These dilute sensitizers a) can give
uneven develoment and b) reduce printing speed. This is explained in
greater detail in a series of posts I made to the list in January/February,
95.
Sandy King
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